In prior an cryogenic fire extinguishing devices, difficulties of maintaining cryogenic extinguishant materials in storage are encountered because, among other things, of the steep temperature gradient between storage facilities and the inner wall of the cryogenic material container.
In some pre-pressurized bottle systems problems are encountered with respect to the solubility of a pressurizing agent into the extinguishant material resulting in an overall loss of pressurization and thus, an inefficient scattering of the fire retardant material.
In systems requiring the detonation of an explosive charge for actuation, it is necessary that the charge and its detonating mechanism be periodically inspected and, if aging is a debilitating factor, be renewed or replaced. In some prior art systems, it is necessary that the detonation device be manually armed prior to deployment.
In almost all utilizations of fire extinguishing devices it is important that the apparatus and method used to put a fire out not be more expensive than the protected premises nor be too complicated for facile deployment.
The instant invention intends the overcoming of difficulties encountered in the prior art as delineated above.
The prior art includes U.S. Pat. No. 1,149,975, to A. L. Cole for Fire Extinguishing Bomb, issued Aug. 10, 1915. The device described in the Cole patent provides an in situ device adapted to be placed in a room in which a fire may occur. The device is intended to replace or be used instead of a sprinkler system or the like and contemplates a frangible glass bottle to contain the fire retardant material employed for the purpose of extinguishing the fire.
Another prior art device is described in the U.S. Pat. No. 1,453,091 granted to H. E. Delbare for Means for Extinguishing Fire, issued Apr. 24, 1923. Delbare contemplates another in situ device to be activated upon extreme temperature elevation thereby causing a deposition of solder to melt so as to release a springed striking device thus activating a detonator and causing atomization of a liquid fire extinguishant. Again a glass receptacle is employed to contain the extinguishing material. The glass receptacle is intended to be burst into pieces by the explosion started by the detonator thereby deploying the fire extinguishing material.
Yet another prior art device has been illustrated in the U.S. Pat. No. 4,285,403, granted to Poland and issued Aug. 25, 1981, for Explosive Fire Extinguisher. In the Poland invention, an explosive charge is located substantially in the center of a frangible, spherical shell containing an aqueous solution. The combination of droplets formed in the explosion of the device, fire retardant chemicals contained in the droplets, displacement of oxygen supporting the fire and the concussive force of the explosion acts to extinguish the fire.
U.S. Pat. No. 4,637,472, granted to Decima for Rapid Discharge Extinguisher issued Jan., 20, 1987, describes another prior art device intended for use in situ in an area used for storing explosives and activated by a detonator subsequent to detection of a fire.
Patentee Sassier's U.S. Pat. No. 4,760,886, for Fast Discharge Fire Extinguisher and a Method of Fabricating Same, granted Aug. 2, 1988, is essentially the same as the Decima device as indicated by Sassier at column 1 in his Description of the Prior Art, but claiming lower cost.
U.S. Pat. No. 5,327,732 issued to DeAlmeida on Jul. 12, 1994 for Apparatus for Supplying Cryogenic Fluid, Namely Nitrogen, to Extinguish Fires describes a highly complicated and sophisticated apparatus including a microprocessor used in controlling nitrogen flow and vaporization. The device appears to be intended to be transported to the fire scene on a wheeled carriage.
An additional prior art U.S. Pat. No. 2,328,491, for Bomb Comprising a Compressed Mass of Fire Extinguishing Powder, to E. Puchner issued Aug. 31, 1943, uses a molded mass of fire retardant powder to be exploded so as to disperse the material and thus to end the fire. The molded mass of extinguishant is not encased in any container, rather it is held together by a binding agent.
The U.S. Pat. No. 2,349,980, issued May 30, 1944 to L. W. Moore for Forest Fire Extinguisher contemplates an extinguishing powder deployed upon detonation of an explosive charge through contact of a nose trigger on the bomb-like device.
In U.S. Pat. No. 3,980,139, issued Sep. 14, 1976 to N. Kirk for Fire Extinguishing Bomb for Putting Out Fires the fire retardant is scattered by an explosive charge and is to be installed in a building or the like or is to be dropped on a fire.
Still another prior art patent tamed up in applicant's pre-examination search bears U.S. Pat. No. 4,319,640 and the title Gas Generator-Actuated Fire Suppressant Mechanism. It was issued to Karl R. Brobeil on Mar. 16, 1982. The innovative device contemplates suppression of fires in military vehicles. Fire retardant liquid is expelled via a duct so as to be directed and is actuated by means of a detonating system.
The penultimate prior art patent presented herewith is U.S. Pat. No. 5,232,053 for Explosion Suppression System issued to Gillis et al on Aug. 3, 1993. The device described therein contemplates an explosive actuated mechanism wherein an explosion suppressant is directed by means of a duct. An explosion protection system is described and claimed rather than a fire extinguishing system, however, in the interest of thorough disclosure of prior art patents discovered in applicant's search, this less relevant patent is included.
The final prior art patent discovered in applicant's pre-examination novelty search and cited herewith is U.S. Pat. No. 4,328,867 and was granted to Richard C. Heath on May 11, 1982, for Fire Extinguishers. The patent describes a system having a diaphragm, burstable by means of a detonated explosion that is controlled by an electric circuit.
These prior art devices are commendable and show a creative spirit for their times. The inventors and their inventions have contributed remarkably to the technology involved. However, these prior art structures do not include those combined elements of the instant invention that provide greater facility of use and ingenious arrangement of components and that make the instant invention the high culmination in the art.